Not done much kettlebell work but used to get callouses from lifting weights (as above deadlift probably being the main culprit). Improved my grip - holding the bar with fingers rather than palm, if that makes sense - and they have all but disappeared. I also use chalk which helps a lot with grip.

I can't see any reason to use gloves whilst weight lifting and would assume the same would follow with kettlebells.

Not kettle bells or weights, but similar force on the fingers: If I've not been climbing for a while (months) and I get too excited on the overhangs too soon, the skin can't handle the pulling and I get blisters on my fingers which lift and expose raw skin. ow. tape helps.

Once I've been back at it for a bit, the sin toughens up and it ain't no thang.

I used to get blisters when doing 4 workouts a week and still do occasionally. Best way is to get your hands used to it. I did try gloves for a bit, but found that grip would worsen and the rubbing would cause blisters between the fingers.